This invention relates to the field of surgery and more particularly to a tool useful for performing anastomoses and skin closures.
The term "anastomosis" covers a variety of procedures in which blood vessels or other tubular members, such as parts of the colon, are joined or reconnected. Vessels may be joined in a variety of relative orientations, including end-to-side, and end-to-end. Solid tubular structures such as peripheral nerves can also be joined together, as well as solid structures such as subcutaneous tissue and skin.
Anastomoses are traditionally performed by suturing the vessels together at the juncture between them. Alternatives to suturing have been developed, in order to prevent thrombosis which tends to occur at the points of penetration of the sutures. One such alternative, particularly for larger vessels, involves mechanical connectors such as collars. A second alternative is the use of surgical clips which are applied along the vessel juncture to perform a holding function similar to that of sutures, without penetrating the vessel walls. Two such clips, developed by the present inventors, are shown in U.S. Pat. Nos. 4,586,503 and 4,733,660. As described in the former patent, the clips are applied over apposed edges of the vessels, the edges first being everted (turned outward) to form flanges that are gripped between the jaws of the clips. Eversion not only gives the clip jaws a better purchase on the vessels, but also insures that only the interior surfaces of the vessels are in contact.
The use of non-penetrating clips requires that the vessel or tissue edges be accurately and symmetrically everted. Correct eversion is critical at the beginning of anastomoses and at difficult sites, such as at the heel and toe of an end-to-side anastomosis.
Proper eversion is difficult to achieve, since the tension along the periphery of the flange creates an unstable situation between lower-stress alternatives of the original uneverted configuration and a configuration in which the flange folds back over the vessel to form a cuff. The fact that surgical clips have proven fast, simple to apply and reliable in their holding ability, has accentuated the need for a tool to assist a surgeon in everting vessels while performing anastomoses.
Clips are typically applied with a small hand-held tool that enables the surgeon to place precisely the clip over the tissue edges, and then to close the clip, as by applying a squeezing pressure to the tool. It is desirable to enable the same surgeon to perform the required vessel eversion, with his free hand.